1. Field of the Invention
The invention relates in general to a bobbin of transformer, and more particularly to a bobbin module of transformer capable of decreasing mold cost and increasing pressure resistance.
2. Description of the Related Art
With the popularity of multi-media products, the application of liquid crystal display (LCD) such as computer monitor and LCD TV is also becoming more and more popular. Typically, the LCD adopts slim and high efficient lamp tube driving system as the backlight, so that the thickness is reduced and that the display quality is improved. The lamp tube driving system of an LCD mainly consists of a cold cathode fluorescent lamp (CCFL) discharge lamp tube and a transformer used for driving the CCFL. Under the current trend of large-scaled LCD, the number of the lamp tubes is increased and the scale of the lamp tube enlarged. Consequently, the lamp tube driving voltage is increased. For example, the lamp tube driving voltage is increased from 1 KV to 3 KV and above, and the number of turns of the primary coils and the secondary coils are increased accordingly.
Conventionally, two bobbins are combined to provide more turns of the primary coils and the secondary coils. If two bobbins are combined to form a bobbin module, the combination must include one male bobbin and one female bobbin, and the two dimensional positioning for assembly can only be achieved in the x direction and the y direction. However, if the design of coupling one male bobbin with one female bobbin is adopted, two different molds are required to manufacture the male bobbin and the female bobbin respectively. Thus, the mold cost will be increased. Besides, when the bobbin module is hit by an external force, the two bobbins of the bobbin module may separate in the z direction.
Furthermore, after a conventional bobbin is wound in the primary coil and the secondary coil, the bobbin will form a transformer with an iron core. Then, the transformer is enclosed by the tape. However, the process of enclosing the bobbin, the coil and the iron core with the tape is very time-consuming and difficult, and the material cost for the tape is significant. Since the conventional transformer whose bobbin, coil and iron core are enclosed by the tape has a poor performance in pressure resistance, the conventional transformer is difficult to meet the requirements of the current trend of enlarging the scale of LCD panel and increasing the voltage of the lamp tube driving voltage.